Integrated design of MOFs-derived 0D/1D/2D/3D hierarchical network for high-efficiency electromagnetic wave absorption

To overcome electromagnetic pollution issues, multi-dimensional carbon-magnetic composites have gained attention. In this study, a 2D nanosheets stacked 3D network with 0D Co particles and 1D CNTs was synthesized via hydrothermal and annealing method. The nitrogen-doped porous 3D crosslinked network constructed with intertwined 1D and 2D components (CNTs, PDA-derived carbon, and MOFs-derived carbon) effectively extends the propagation pathway, providing superior conductive loss. Moreover, the 3D magnetic-electrical porous heterostructure greatly enhances the multiple scattering and reflection of the incident waves, as well as induces excellent eddy current loss. In addition, 0D Co nanoparticles exhibit multi-mode magnetic resonances and optimize impedance matching characteristics to capture more electromagnetic waves (EMWs). The microstructures, consisting of rich defects and multilevel heterogeneous interfaces, stimulate multidimensional advantages to regulate relaxation time for optimized dipolar polarization and interface polarization. Consequently, the multidimensional Co/CNTs@C heterostructure displays an optimum absorption of −59.1 dB at 11.3 GHz (loading of 10 wt%) and an ultra-width effective absorption band (EAB) of 8.1 GHz (20 wt%). Relevant simulation experiments demonstrate the strong absorption and extremely poor reflection, testifying its surprising performance. Overall, this work provides a novel strategy for preparing MOFs-derived multidimensional EMW absorbing materials.